The present invention is directed to an adjustable chair which typically has a seat assembly, a backrest, and a support structure. An adjustable chair may have various adjustable features that can be modified by the occupant to fit the most comfortable sitting position. Adjustability includes tilting of a backrest relative to the seat and raising or lowering the seat. To achieve the most comfortable sitting position, the chair has to be adjustable to relieve the pressure on the occupant's spine, tailbone, and pelvic bone in sitting position. Adjusting the seat position would require the occupant to manually operate the individual mechanics of the adjustable parts of the chair. Thus, it would be desirable to have an automatic adjustable chair with electrically motorized drive system that is operable through a controller unit while in sitting position.